Notes Receivable and Allowance for Credit Losses - Allowance for Credit Loss Rollforward (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 19,484	$ 4,556
Provision for Loan and Lease Losses	134	7,634
Write-offs	0	(1,054)
Ending balance	19,618	19,484
Cumulative Effect, Period of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 0	8,348
Ending balance		$ 0